Process of extracting milk oil



Patented Mar. d, 119241. I Y

unit as at 11cc. 1

CHARLES E. NORTH, OF MONTCLAIR, NEW JERSEY, AND GEORGE C. PECK, OF POTSDAM, NEW YORK, ASSIGNORS TO THE MILK OIL CORPORATION, OF WILMINGTON, DELA- WARE, A. CORPORATION OF DELAWARE.

PROCESS OF EXTRACTING MILK OIL.

No Drawing. Application filed April 11, 1923. Serial No. 631,353. T all whom, it may concern: ing the serum to consist only of water in Be it known that we. CHARLES E. Non'ril which all other solids other than the fat are and Gunner: C. Pl-ICK, both citizens of the suspended or precipitated, the serum would United States of America, residing at Montloseentirely its property of holding the fat clair, in the count of Essex and State of in the form of an emulsion.

New Jersey, and 1 otsdam, in the county of One, and generally, the most important St. Lawrence and State of New York, restep in the breaking of the emulsion is its spectively, have invented certain new and dilution with water, as this reduces the relusetul Improvements in Processes of Ex ative amount of the casein and other non fattracti'ng Milk Oil, of which the following is solids in proportion to the quantity of dilua full, clear, and exact description. tlon water added. In general the amount of In processes heretofore practiced for the fat recovered by the application of heat to recovery of oil in a pure state from milk such dilutions depends upon the extent to and cream two more prominent ditiieulties which such dilution is carried. have been encountered; one the breaking of Separation .by centrifugal action conthe emulsion so as to secure a complete to tributes materially to the separation 01' the alescence of the fat globules; the other the fat and hence in this process it is desirable complete separation from the tat ot' the and customary to repeatedly dilute. and to casein, the other solids not fat and the pass the. dilution through an ordinary cream \vater. separator, by which means a washed cream For purposes of the present case the is readily obtained in which the stability of problems involved in these two steps may the emulsion is very greatly weakened by the be briefly and separately considered notremoval of the emulsifying forces of the milk withstanding the factthat the solution of serum. By this means the solution of the two one assists in certain respects the proper problems, and particularly the second named, solution of the other. may be closely approximated but not com- The emulsion of fat in milk and .cream pleted, for the last vestige of casein reso is maintained by the milk serum or what maining clings pertiuatiously and persistis more commonly known as the skim milk. ently to the fat. globules so that even after This is composed of water, casein and at many dilutions and centrifugal separations bumen in colloidal suspension, sugar and the final product is still an emulsion and salts in solution, and by its viscosity itholds has the physical appearance of cream, this the milk fat in emulsified form under all being due to the presence 01" the remanent natural conditions. This property is not casein. possessed by water alone for a mixture of The coagulation of the casein in natural milk fat and pure water is so unstable that milk reduces the viscosity of the milk serum under the influence of gravity alone the two by throwing the colloidal suspension out of are spontaneously separated into a layer of its solution, but coagulation in such cases water and a supernatant layer of fat or oil. introduces another obstacle to the separation The presence in the milk or cream, thereof the fat because of the interference and fore, of the solids, not fat and f hi h clogging of the mixture by the solid flakes the casein forms the chiet ingredient, is of coagulum which not only entangle the mainly responsible for the permanency of fat globules and prevent their rising under the emulsion which we know as milk or the influence of gravitation, but quickly cream. As above stated this casein in close up the spaces and orifices of the connatural sweet milk is in colloidal form, or trifugal separator so that the flow of serum in other words, it exists in a fine jelly-like and fat through the machine is very quickly suspension, which adds very materially to arrested.

the viscosity of the milk serum. In all cases where curds or the coagula- It is manifest that c'ould'this casein totion above referred to occur in the milk or get-her with the other solids, not fat, be cream whether naturally as by the soaring thrown out of the solution or he changed of the cream, or artificially, as by the addiinto solid form and Withdrawn as such, leavtion of coagulating reagents of any kind,

- to clog up the separator.

some additional stepsare necessary to obtain a separation and agglomeration of fat globules and the removal of the curds. Such steps are by whipping or churning the cream and by sedimentation or washing and draining before the fat is sufficiently free to be purified and dehydrated. For these reasons the formation of curds in natural sweet milk and cream by artificial means is to be avoided, if the process of recovering the fat is to be greatly simplified.

We have found, however, that if the skim milk with its casein content be almost wholly washed away from the fat by repeated dilutions and centrifugal separations, artificially promoted coagulation of the casein may be resorted to with great advantage, because the quantity of this ingredient is so relatively insignificant that it does not interfere with the separation of the fat nor tend For example, three dilutions and separations of say ten cans of whole milk, if properly carried out, will produce one can of washed cream containing about 351 24: fat and less than 1% of the casein originally present in the milk. If by means of a 'curdling reagent this remanent casein be coagulated, the stability of the emulsion is broken to such an extent that the fat may be separated out either by passing the same through any suitable 'form of filter which will permit the passage of the oil and water but arrest the coagulated particles of casein, or by diluting and heating the mixture until the fat accumulates on the surface when the subnatant dilution water may be drained oil. The product in either case may then be passed through an ordinary whey separator to throw off most of the water and any vestige of casein that may remain in the oil, and then passing this concentrated fat through an oil separator or dehydrator to remove the last vestiges .of water.

In carrying out this invention we use rennet as the proper curdling reagent for the coagulation of the casein, as this we have found to be the best substance for this purpose as it produces a curd which produced by rennet falls away from them so cleanly that they are completely released from its embrace. Rennet therefore lends itself with peculiar and decided advantage to the process of fat separation, as may be seen by the fact that if a few drops be added to a can of doubly washed cream and the latter permitted to stand for a few moments the fat globules are freed so completely that their separation is spontaneous. So complete is this separation that without filtration, prolonged sedimentation or-drainage the cream may be passed at once through a whey separator, preferably with the addition of about four parts of water to one of cream, and a pure clear oil produced in one operation. This oil may then be further dried by means of an oil separator.

No special nor new forms of apparatus are required in carrying out this process. The machines herein described as cream separators, whey separators and oil separators are all well known devices in this art and require no special description.

What we claim is- 1. In the fat from milk or cream, the steps herein described of washing the cream separated from the milk, curdling the'remanent casein in the washed cream by the addition of rennet and separating out the oil therefrom.

2. In the process of. recovering oil or fat from milk and cream, the steps herein described of washing the cream separated from the skim milk, curdling the remanent casein in'the washed cream by the addition of rennet, diluting the cream and separating and purifying the oil by centrifugal action.

In testimony whereof we hereto 'a-flix our signatures.

CHARLES E. NORTH. GEORGE C. lPlECK process of recovering oil or 

